Hi ELAL...
While I do not personally support the use of the loop belt (also known as a belly belt), its use is mandated over much of the world for lap held infants and I understand the rationale for that. Outside of North America, regulatory authorities might view the FAA as not being safety-conscious as they permit lap held infants to travel without any means of restraint.
EU-OPS does require that all occupants are restrained using a safety belt, harness or restraint system:
OPS 1.320 Seats, safety belts and harnesses
(b) Passengers
1. Before take-off and landing, and during taxiing, and whenever deemed necessary in the interest of safety, the commander shall ensure that each passenger on board occupies a seat or berth with his/her safety belt, or harness where provided, properly secured.
2. An operator shall make provision for, and the commander shall ensure that multiple occupancy of aeroplane seats may only be allowed on specified seats and does not occur other than by one adult and one infant who is properly secured by a supplementary loop belt or other restraint device.
COMMISSION REGULATION (EC) No 859/2008 (EU-OPS)
I feel that the bigger question is the ability to travel with an infant on your lap and how to adequately restrain that item of mass in the event of an incident or accident. While not perfect, most aviation regulatory authorities have elected to require the use of the loop belt as it provides a level of protection during normal or abnormal operations and periods of in-flight turbulence not afforded to an unrestrained infant. In the event of an accident, neither the loop belt nor unrestrained lap infant is ideal, for many reasons. In relation to the loop belt specifically, a number of studies have been conducted to evaluate its effectiveness in an accident. Although a worst-case scenario, the following reports summarize the primary hazard associated with its use:
"In a suddenly occurring deceleration in the longitudinal aircraft axis, the adult and the infant show a pronounced jack-knife effect. The upper torso and the lower extremities of the infant as well as of the adult sitting behind the infant fold up in a forward direction, with the loop belt restraining the infant. Finally, the loop belt drives into the infant's abdomen and only stops at his or her vertebral spine. From the technical point of view, the infant acts like an energy absorption element for the adult; the crash loads acting on the adult are thus reduced, and the infant fixed with the loop belt thus suffers most serious up to fatal injuries."
Examination on the Enhancement of Cabin Safety for Infants
"The data and observations from the four tests with the belly belt did not produce any favorable results. The impossibility of protecting a small child, by any means, sitting on the lap of an adult restrained by seat belts was confirmed in these tests. Severe contact with the forward row seat back was observed during double row tests. The recorded head impact of the 6-month old CRABI ATD resulted in a HIC above 1900. Abdominal pressures from the CAMIX ATD were 50% greater than data from booster seats under similar conditions. Aft row occupant impact on the breakover seat back resulted in a definitive peak in the abdominal pressure data. Based on the biomechanical data as well as observations of the films from these tests, the belly belt should not be construed as means of protecting small children."
The Performance of Child Restraint Devices in Transport Airplane Passenger Seats
In the end, I feel that the safest method to transport an infant is in their own passenger seat, using a restraint system that has been approved for use on board aircraft (whether a car seat or one specifically designed for aircraft use, such as the
CARES).